Aggressive dual pin track



June 4, 1963 L. SPEIDEL, JR, ETAL 3,092,423

AGGRESSIVE DUAL PIN TRACK Filed April 25 1961 5 Sheets-Sheet l INVENTORSSPEIDEL. JR.

June 4, 1963 L. SPEIDEL, JR, ETAL AGGRESSIVE DUAL PIN TRACK 5Sheets-Sheet 2 Filed April 25, 1961 FIG.3

INVENTOR. LOUIS spawn, an. :owmn J. sow. .m.

June 4, 1963 SPEIDEL, JR., ETAL 3,092,423

AGGRESSIVE DUAL PIN TRACK Filed April 25, 1961 5 Sheets-Sheet 3INVENTOR. ls spawn, JR.

X04. 2250a, ad. 24 Hm United States Patent 3,092,423 AGGRESSIVE DUAL PINTRACK Louis Speidel, in, Royal Oak, and Edward J. Gow, In, flak Park,Micln, assignors to the United States of America as represented by theSecretary of the Army Filed Apr. 25, 1961, Ser. No. 105,524 7 Ciaims.(Cl. 395-11) (Granted under Title 35, US. Code (1952), see. 266) Theinvention described herein may be manufactured and used by or for theGovernment for governmental purposes, without the payment to us of anyroyalty thereon.

This invention relates to a track for track-laying vehicles.

More particularly, the object of our invention is to provide aconnecting pin arrangement which results in a greater portion of a giventrack shoe width being used for grouser. Specifically, this arrangemententails the use of dual axially separated track pins in lieu of theprior art single pin connector Whose length thereof is longer than thecomposite length of the dual track pins. The use of dual pins enablesthe space previously occupied by the long single pin connector and itsassociated bosses to be utilized as a trap for soil which would not haveordinarily entered between the track shoes. The additional soilentrapped between adjacent shoes serve to greatly increase the tractionbetween track and ground and insures aggressiveness of the track in alltypes of terrain.

A further object of our invention is to provide a number of differenttrack pin designs that can be used to implement our dual pinarrangement. Accordingly, we have designed track pins for use with atrack-laying vehicle that result in a track with no decrease in abilityto absorb tensile stresses but with a high degree of grousing abilitydue to the small amount of space occupied by our PlIlS.

A further object of our invention is to provide a pin arrangement thatwill result in easier pin installation and removal. The installation andremoval of the prior art single pin connector is difiicult due to thefact that such a pin must pass through up to five bosses in order toconnect or disconnect adjacent track shoes of a given width. This meansa great deal of friction must be overcome in order to install or removea single pin connector. Further, the removal of a single pin connector,bent by differential movement of the bosses may be very ditlicult. Theuse of our dual pin arrangement with adjacent track shoes of the abovewidth greatly relieves or eliminates the above difiiculties since it isnecessary for each pin of the dual pin arrangement to pass through onlytwo bosses and in one of our designs through only one boss.

With the foregoing and other objects in view, the invention resides inthe novel arrangement and combination of parts and in the details ofconstruction hereinafter described and claimed, it being understood thatchanges in the precise embodiment of the invention herein disclosed maybe made within the scope of what is claimed without departing from thespirit of the invention.

In the drawings:

FIG. 1 is a perspective view of two connected track shoes utilizing ourconnecting pin arrangement.

FIG. 2 is a plan view of the track shoes illustrated in FIG. 1.

FIG. 3 is an elevational view of one embodiment of our connecting pinengaging adjacent track shoes with portions of the pin and track shoesbeing shown in section.

FIG. 4 is an elevational view of another embodiment "ice of ourconnecting pin engaging adjacent track shoes with portions of the pinand track shoes being shown in section.

FIG. 5 is a plan view in section of another embodiment of our connectingpin with portions of the connected track shoes being shown broken away.

FIG. 6 is an enlarged transverse sectional view of an alternate sealingring that can be used with our invention.

FIG. 7 is a section taken through line 7-7 of FIG. 5.

'FIG. 8 is a view similar to FIG. 7 showing alternate attaching means.

Referring now specifically to the drawings, FIG. 2 illustrates two trackshoes of an endless track utilizing our connecting pin arrangement. Theuse of our dual connecting pins (contained Within bosses 2 and 4)enables the spaces 6, 8 and 10, previously occupied by the prior artsingle pin connector and associated bosses to be utilized as a trap forsoil which would not have ordinarily entered between track shoes 12 and14. This additional soil entrapped between ground contacting track shoesserves to greatly increase the traction between the track-laying vehicleand ground and insures aggressiveness of the vehicle in all types ofterrain.

Although FIG. 2 shows specific details of the track shoe body (theportion of the track shoe with the exclusion of the pins and bosses), itis not per se to be considered part of the invention, and it is to beunderstood that this invention is not limited to use with a specifictrack shoe body but is to be considered equally useful with shoes ofdifferent designs.

Referring to FIG. 3, there is illustrated one of our dual axiallyseparated track pins 16 engaging adjacent track shoes 12 and 14. Thecomposite pin 16 is composed of three elements: the body member 18, stem20, and locking plug 22. The body member 18, in turn is made up ofcylindrical journal 24, cylindrical segment 26, a tapered portion 28connecting the ends of the cylindrical segment 26 and journal 24, andknurls 30 provided on cylindrical segment 26. The surfaces of all theabove parts are designed to engage and mate with internal portionsprovided in bosses 2 and 4, it being understood that a key and keywaycould be substituted for knurls 30 if so desired.

Body member 18 is further provided with bore 32 designed to receivethreads 34 near one end of stem 20. The other end of stem 20 is providedwith threads 36 which are of much greater pitch than threads 34 for apurpose to be discussed hereinafter.

The connection of track shoes 12 and 14 is accomplished by firstpartially threading stem 20 into body member 18, after which theattached members are inserted through bearing boss 2 and on through boss4 until threads 36 of stem 20 engage the internal threads provided inboss 4.

A large rectangular recess 38 is provided in body member 18 so that thepolygonal head 46 on stem 20 can be easily reached and turned by aninserted tool. The recess 38 also serves to lighten body member 18 andultimately the track.

Stem 20 is now threaded into boss 4 by the turning of polygonal head4t). As the stem moves into boss 4, body member 18 is pulled intoengagement with the internal taper and knurls of boss 4. This ispossible due to the pitch of threads 36 being large in relation to thepitch of threads 34-. Thus, as stem 20 is threaded into boss 4, threads36' pull stem 20' and body member 18 a greater distance in relation toboss 4 than threads 34 move body member 18 on stem 26. It is evidentthat if stem 20 was integral to body member 18 the ability to turn stem20 and draw body member 18 into contact with the internal knurls of boss4 would cease as soon as knurls 30 came into contact with the internalknurls of boss 4. Thus, threads 34 allow stem 20 to turn within bodymember 18 while threads 36 pull body member 18 into tight engagementwith boss 4.

When stem 20 can no longer be turned, body member 18 has been drawn intotight engagement with boss 4. The stem is now prevented from turning inbody member 13 by locking plug 22. Locking plug 22 is designed with anoutside surface that mates with the internal surface of recess 38 and aninside recess that mates with the polygonal surface of head 4%. Thus,when locking nut 22 is placed in the position shown in FIG. 3, there canbe no relative movement between body member 18 and stem 29. Pin 16 isnow positively fixed within boss 4 and cannot be removed until lockingnut 22 is removed and the above procedure reversed.

As seen from FIG.- 3, pin 16 is positively fixed to track shoe 14 andjournaled to track shoe 12 through journal 24. The tensile load onjournal 24- is transmitted to bearing boss 2 through the bearing 42which is press fitted within boss 2. Bearing 42 is preferably made froma material such as Telflon or Oilite, which are both widely used forlubricating bearings. The bearing boss cavity (and bearing therein) areprotected from weathering by providing a self-locking threaded plug 44on its outer end and a sealing ring 46 on its inner end. The plug 44 isprovided with a recess 47 adapted to receive a tool which can loosen ortighten the plug in its seat. Sealing ring 46 is preferably made fromnatural or synthetic rubber and is also press fitted within boss 2. Ametal ring 48 made from a beryllium-copper alloy is joined to the innersurface of sealing ring 46 so that it is in continuous engagement withjournal 24' 'This metal ring eliminates the friction and wear that wouldoccur if the rubber seal 46 directly engaged journal 24.

Sealing ring 46 may be replaced, if desired, by rubber sealing ring 59,a section through which is shown. in FIG. 6. In assembled position,outer surface 52 of seal 50 is press fitted within bearing boss 2 whileits inner surface 54 is stretched over journal 24. The rotation ofjournal 24 within boss 2 results only in the twisting of web 56 of seal50- and in no relative movement between the inner surface of boss 2 andouter surface 52 and between journal 24 and inner surface '54; Since theinner and outer edges of Web 56 will be twisted in relation to oneanother through the same maximum angle of only 30 that adjacent trackshoes are'rotated in relation to one another, the small amount of stressplaced upon rubber web 56 can be easily absorbed without damage. It isnoted that our 'dual pin arrangement requires the use of only twosealing rings of the type described above for a connection between twotrack shoes while a track shoe connection using the single pin connectormay require many more since the pin passes completely through each boss.

The alternate pin design illustrated. in FIG. 4 ditfers from thestructure of FIG. 3 only in the manner that body member 18 is drawn intoboss 4.; This entails the substitution of bolt 58 for stem 20 andlocking nut 22. The use 'of the structure illustrated in FIG. 4 isadvantageous from the point of view that it uses fewer and less complexparts than the structure of FIG. 3 but it is less eflicient in thatmoisture may enter under bolt head 66* and travel into the interior ofboss 4. Further, if bolt 58 is not sufiiciently tight it mayloosen dueto the continuous vibration it is subjected to. This naturally willresult in the disengagement of body member 18 and boss 4, an event whichis improbable when using the positively locked structure of FIG. 3.

As an alternative to the use of bolt 58 as means to draw body member -18into boss 4, a threaded stud may be formed on body member 18. After thestud is passed through boss 4, body member 18 is drawn into boss 4 bythreading a nut on the projecting stud. Recess 62 shown in FIG. 4 isprovided in body member 18 so as to lighten the track. It in no waydecreases the tracks ability to absorb tensile stresses.

The embodiment of FIG. 5 features pins 64 integral with track shoe 14.This permits the elimination of two bosses per connection and theforming of pins 64 so as to occupy a minimum of space. The resultingtrack is one that will provide grouser capability greater than that ofthe tracks formed from the structures of FIGS. 3 and 4, due to theadditional space available for soil entrapment.

The bearing boss 66 shown cooperating with pin 64 is basically the sameas the bearing bosses illustrated in FIGS. 3 and 4 with the exceptionthat it is made separable from track shoe 12. When it is desired toconnect the track shoes, bearing boss 66 is attached to track shoe 12 bybolts 68 and 70,215 shown in FIG. 7, or by means of a tongue and groovejoint with a round tapered pin lock 72, as shown in FIG. 8. It will,however, be understood that these are merely examples and are not givenby way of limitation, since we may employ other attachment arrangementswell known to those skilled in the art. When the track shoes areawaiting connection, the bearing bosses 66 are engaged with journals 74so as to ensure that no moisture or dirt will enter the bearing cavity.Recess, shown in FIG. 5, is provided in pin 76 for the same purposerecess 62 was provided in FIG. 4.

Each of the pin embodiments of FIGS. 3, 4 and 5 result in providingreduction of seal points to one for each pin, ease of installation andremoval of pin, and a track shoe with a minimum of 40 percent of itswidth being used for full aggressive grouser.

We claim:

1. An endless track, embodying articulated track shoes, 7

each shoe comprising first and second longitudinal sides, a pair ofspaced bearing bosses each formed with a cavity therein secured to saidfirst longitudinal side, dual axially spaced separate track pins,extending from said second longitudinal side of each of said shoes, eachpin having one end extending into the cavity in the bearing bosses ofadjoining shoes, said bearing bosses being formed to completely coverone end of said pin, sealing means disposed in the cavity of each ofsaid bearing bosses between each said pin and its respective bearingboss to completely enclose the end of said pin within the confines ofsaid bearing boss, said bearing bosses and pins occupying a space thatinsures a minimum of 40% of said first longitudinal side being used forfull aggressive grousing, bearings disposedbetween each said pin andeach said boss, each shoe having bearing bosses integrally formed onsaid second longitudinal side, fastening means engaging each of saidlast mentioned bosses for detachably securing said pins to said lastmentioned bosses, said track pins comprising a body portion providedwith knurls corresponding to knurls formed within said bosses on saidsecond longitudinal side, said last mentioned means being formed by astem provided with first and second portions threaded, respectively, tosaid body portion and to said last mentioned bosses, and locking meansadapted to be disposed between said stem and said track pins to arrestall relative movement between said body portion and stem after said bodyportion has been drawn into engagement with said bosses by rotation ofsaid stem.

7 2. The endless track of claim 1 wherein the pitch of the threads ofsaid first portion is smaller than the pitch of said second portion.

3. The endless track of claim 5 wherein a recess is provided throughsaid bearing bosses on the first longitudinal side of one shoepermitting insertion of said track pins into said bosses on said secondlongitudinal side of an adjacent shoe, said recess also permittingaccess to and rotation of said stem within said body portion, and aselflocking plug threaded into said recess after said pins arepositively engaged to said bosses.

4; An endless track embodying articulated track shoes, each shoe havinga first pair of spaced bearing bosses extending beyond one side thereofand a second pair of spaced bearing bosses extending beyond the oppositeside thereof, means pivotally connecting said first pair of bosses on afirst shoe to said second pair of bosses on a second shoe, said meansformed by spaced track pins, each pin defined by a body member having atapered portion and a cylindrical journal extending therefrom, each ofsaid second bearing bosses having a tapered recess therein adapted toreceive the tapered portion of each pin, threaded means threadedlyconnecting each of said track pins to each boss of said second bearingbosses, said last mentioned means having a head portion so that thethreaded means may be turned in one direction to secure the pins withinthe second pair of bosses and turned in the opposite direction to movesaid pins out of said first bearing bosses, said cylindrical journal ofeach pin extending beyond each of said second bosses and connected toeach of said first bosses, said cylindrical portion being confinedwithin said first boss, each of said first bosses having a removablejournal to provide access to said cylindr-ical journal, each of saidthreaded means being formed by a stem member having first and secondthreaded portions, said first portion being adapted to be threadedlyconnected to said body portion of each pin and said second portionadapted to be threadedly connected to each boss of said second pair ofbosses.

5. The endless track of claim 4 wherein the pitch of the threads of thesecond portion is greater than the pitch of the threads of said firstportion.

6. A vehicle track comprised of a plurality of shoes, means pivotallyconnecting said shoes to each other, said means comprising a pluralityof track pins, each of said track pins having a tapered body portion anda cylindrical journal, means connecting each pin to each of said shoes,each of said means comprised of an elongated stemmember having a headport-ion and separate first and second threaded portions, said secondportion having threads which are greater in pitch than the threads ofsaid first portion, said first portion being threadedly connected tosaid pin, said second portion being threadedly connected to one of saidshoes.

7. A track pin for articulating the shoes of an endless track together,said pin having a tapered body portion, a cylindrical journal and acylindrical segment, said body portion disposed betweeen saidcylindrical journal and said cylindrical segment, said pin being formedwith a bore therethrough, said bore being threaded near one end of saidpin, an elongated stem member positioned in the bore of said pin, saidstem having a head portion and first and second threaded portions, saidfirst portion being threadedly connected to the threads in said bore,said second portion being adapted to be threadedly connected to one ofthe shoes of the endless track, the threads of said second portionhaving a pitch greater than the pitch of the threads of said firstportion.

References Cited in the file of this patent UNITED STATES PATENTS1,494,568 Allen May 20, 1924 1,956,580 Knox May 1, 1934 2,061,223Cunningham et al. Nov. 17, 1936 2,264,135 Kaminsky Nov. 25, 194-1

1. AN ENDLESS TRACK, EMBODYING ARTICULATED TRACK SHOES, EACH SHOECOMPRISING FIRST AND SECOND LONGITUDINAL SIDES, A PAIR OF SPACED BEARINGBOSSES EACH FORMED WITH A CAVITY THEREIN SECURED TO SAID FIRSTLONGITUDINAL SIDE, DUAL AXIALLY SPACED SEPARATE TRACK PINS, EXTENDINGFROM SAID SECOND LONGITUDINAL SIDE OF EACH OF SAID SHOES, EACH PINHAVING ONE END EXTENDING INTO THE CAVITY IN THE BEARING BOSSES OFADJOINING SHOES, SAID BEARING BOSSES BEING FORMED TO COMPLETELY COVERONE END OF SAID PIN, SEALING MEANS DISPOSED IN THE CAVITY OF THE SAIDBEARING BOSSES BETWEEN EACH SAID PIN AND ITS RESPECTIVE BEARING BOSS TOCOMPLETELY ENCLOSE THE END OF SAID PIN WITHIN THE CONFINES OF SAIDBEARING BOSS, SAID BEARING BOSSES AND PINS OCCUPYING A SPACE THATINSURES A MINIMUM OF 40% OF SAID FIRST LONGITUDINAL SIDE BEING USED FORFULL AGGRESSIVE GROUSING, BEARINGS DISPOSED BETWEEN EACH SAID PIN ANDEACH SAID BOSS, EACH SHOE HAVING BEARING BOSSES INTEGRALLY FORMED ONSAID SECOND LONGITUDINAL SIDE, FASTENING MEANS ENGAGING EACH OF SAIDLAST MENTIONED BOSSES FOR DETACHABLY SECURING SAID PINS TO SAID LASTMENTIONED BOSSES, SAID TRACK PINS COMPRISING A BODY PORTION PROVIDEDWITH KNURLS CORRESPONDING TO KNURLS FORMED WITHIN SAID BOSSES ON SAIDSECOND LONGITUDINAL SIDE, SAID LAST MENTIONED MEANS BEING FORMED BY ASTEM PROVIDED WITH FIRST AND SECOND PORTIONS THREADED, RESPECTIVELY, TOSAID BODY PORTION AND TO SAID LAST MENTIONED BOSSES, AND LOCKING MEANSADAPTED TO BE DISPOSED BETWEEN SAID STEM AND SAID TRACK PINS TO ARRESTALL RELATIVE MOVEMENT BETWEEN SAID BODY PORTION AND STEM AFTER SAID BODYPORTION HAS BEEN DRAWN INTO ENGAGEMENT WITH SAID BOSSES BY ROTATION OFSAID STEM.